Server time zones are all different across Salesforce CRM and Marketing Cloud (and even some different stacks in Marketing Cloud).
Server times for Salesforce Marketing Cloud is in CST: Central Standard Time (UTC minus six hours) and also the server time does not change with standard versus daylight savings time.
There are some weird behaviors with different stacks. Apparently Stack 4 is in US Mountain time (UTC minus 7 hours).
When you sync over data from CRM to Marketing Cloud, the time zones will not match. I've been using the `AT TIME ZONE` SQL function to remedy this. It would be nice to have both systems on the same time zone.